Clear overstep. What a parent gives their child to take to school to eat is their business. If the child is eating school lunches then that’s another thing. Teacher has definitely gotten a big head about shaming people’s dietary choices.
True. That’s my initial thought too. And the passive aggressive note leaves a bitter taste, too. Children naturally like treats and withholding them might create eating disorders too.
You clearly have a lot of faith in humanity if you think parents are always able to feed their kids properly. Heck, a lot of them don't even eat actually healthy stuff themselves.
A teacher sending a message like this is trying to help, not to "snack shame", and reactions like this will lead to even more teachers who don't care anymore and do the bare minimum.
That's a steep price for being "hurt by snack shaming" (whatever the fuck that even is).
Notes on children’s items is not the method of communication a teacher should be using.
As a parent with kids in elementary school, there are 1on1 checkins, assemblies, notifications, community leaders, and more other methods the teacher could have used to discuss this with the parent.
There was zero reason to start labeling the kids lunchbox.